The MD is a vestigial structure that arises from the omphalomesenteric duct (OMD) and connects the embryonic midgut to the yolk sac. It is located on the opposite side of the mesentery in the last part of the ileum, 7-200 cm before the ICV. Its length and diameter range from 0.4–11 cm and 0.3-7 cm, respectively [1, 2]. It is more common in males, with a ratio of 1.5 to 4[2–5]. This ratio is consistent in children, as shown in our study.
MD-associated complications include diverticulitis, bleeding, volvulus, invagination, umbilical anomalies, and tumor development[1, 2, 4, 5].Our study found that diverticulitis and bleeding were the most common complications, which is consistent with the literature [2]. None of our patients developed tumors.
SMD requires surgical removal. The best management of IMD found during surgery for another reason is not clear. In our study, most cases of IMD (70.6%) occurred during surgery for suspected acute appendicitis. In IMD, the surgeon must make a quick decision whether to prophylactically remove the appendix or not, as it is usually not possible to check the surgical margin for ectopic tissue. Some argue against prophylactic removal, citing the low risk of complications in asymptomatic MD and the fact that this risk decreases with age [2, 6, 7]. Others, however, are reluctant to leave IMD unremoved, considering that up to 20% of MD have HM and that removal is more risky if complications occur [2–4]. Furthermore, HM is not the only factor that increases the risk of MD. In our study, 31.4% of IMDs had one or more risk factors (HM, DPB, enterolith). In addition, studies against prophylactic removal did not evaluate the risk of complications from IMD left in the abdomen with surgical adhesions. In our series, the complication rate of unexcised IMD was 22.2%. Cullen reported a lower risk of 6.4% in people under 80 years of age, but still advised prophylactic removal, considering this risk to be high [8].
| Fig. 6: Lineer scatter-dot graphs of length to location of MD | |
Some people argue that prophylactic resection is risky because of the high rate of surgical complications in patients who undergo resection [6]. However, with improved surgical techniques, complication rates have been reported to be lower nowadays. In our study, we found that postoperative complications and the need for reoperation were significantly lower after IMD surgery than after SMD surgery. Some studies in the literature reported no complications after IMD resection [9]. This may be due to the widespread use of laparoscopic surgery, which has a significantly lower complication rate than MD itself[10]. Laparoscopic or laparoscopic-assisted resection of MD has been recognized as a safe and effective method, and it has been suggested that MD detected by diagnostic laparoscopy should be resected laparoscopically instead of converting to laparotomy [2, 11]. In our study, we did not find any significant difference in terms of postoperative complications among patients who underwent laparoscopic, laparoscopic-assisted, and open surgical methods. This may be because we have not reached the learning curve, as shown by the small number of patients who underwent the laparoscopic method.
The management of incidental Meckel's diverticulum (IMD) in adults is still controversial, but the presence of IMD in children is considered a risk factor [3, 12, 13]. Our study showed that IMD in children is associated with a high risk of complications and should be surgically removed. In addition, we found that removal of IMD has fewer postoperative problems than removal of SMD, which supports resection of IMD in children.
There are three possible methods for intraoperative removal of the diverticulum: segmental resection, wedge resection, or simple diverticulectomy. Simple diverticulectomy has become more common with the advent of laparoscopic procedures because it is easier to perform. In our study, none of the patients who underwent simple diverticulectomy (n = 22) had any postoperative complications. However, the effectiveness of simple diverticulectomy in removing all HM within the MD is doubtful. Mukai observed that HM in the MD extends from distal to proximal, and he never found HM only in the proximal part without being in distal part [14]. Based on the embryological theory, since the gastric mucosa does not originate from the midgut, HM differentiates from multipotent cells in the part of the OMD that is distally connected to the yolk sac and therefore spreads into the diverticulum from the distal part [4, 14]. The fact that we did not find HM only in the base of the diverticulum without being in the distal part in any of our patients supports the embryologic theory. Our study also showed that during the first 3 years of life, the MD grows longer and wider and moves away from the ICV. As the MD increases in size, the HM is pushed distally and moves away from the ileodiverticular junction. Our results indicate that MD growth is related to age, confirming Gezer's suggestion that length is related to age [15], but that this growth stops around 3 years of age.
The relationship between the location of the HM and the length of the MD is known, but no morphologic parameter is reliable enough to predict it [16]. Vercoe proposed that the HM is located in the head or body of the diverticulum when the length/diameter ratio is greater than 2 and in the base when it is less than 2 [4]. Mukai suggested a ratio of 1.6 instead [14]. Robijn and Park identified a diverticulum length of more than 2 cm as a risk factor [3, 12]. Slivova and Sinopidis recommended excision of diverticula with diameters greater than 1.5 cm and 2.5 cm, respectively, as they may contain HM [17, 18]. We believe that the different morphological descriptions are due to the different age groups in the studies. Our results show that the growth of the length and diameter of the MD stops after three years of age, so the morphometric values vary depending on the average age of the study groups. Therefore, we suggest that the age of the patient should be considered more than the morphometric measurements of the diverticulum. Simple diverticulectomy may be risky in the first three years because possible HM content may not have migrated distally.
Simple diverticulectomy, which Glenn advocates for patients with bleeding, is widely considered to be unsafe [16, 19–22]. Our histopathologic analysis showed that patients with HM extending to the ileodiverticular junction always presents with bleeding or pOMD. The ulcers that cause bleeding are located in the intestinal mucosa near the HM and often in the diverticulum neck, which is completely covered by the gastric mucosa[23]. Thus, in bleeding or pOMD patients, the HM may spread to the ileodiverticular junction and simple diverticulectomy may not remove all of the HM.
A limitation of the study is that a clear age-cut-off value for diverticulum extension could not be determined, despite the Loess Scatter dot plot indicating that it continued until around three years of age. Additionally, the number of diverticula containing HM was small. A higher correlation coefficient between the lengthening of the diverticulum and the distal displacement of the HM can be demonstrated in a more extensive series.
To improve surgical outcomes, we need to rethink how we treat IMD. Many children with IMD have risk factors and complications can arise if IMD is not removed. Therefore, removing IMD is better than leaving it inside the abdomen because it has a very low risk of complications. Cutting off MD with simple diverticulectomy is becoming more common in laparoscopic surgery because it is easy to do. However, there is not much evidence in the literature that this procedure works well for removing HM. Our study shows that MD grows until the child is three years old and HM moves further away from the diverticulum. In younger patients, HM may not be far enough from the border of the diverticulum. Also, based on our findings, patients who have HM reaching the border of the diverticulum always have bleeding. Therefore, simple diverticulectomy may not remove all of HM in patients younger than three years old or in patients who have bleeding or pOMD.
Our study's findings are likely to have a positive impact on the treatment of Intestinal Malrotation and Volvulus (IMD) in children. We are hopeful that this congenital intestinal anomaly will no longer be left untreated due to the insights gained from our research. Additionally, our study may help us better understand the limitations of simple diverticulectomy, which has become increasingly popular with the advancement of laparoscopic techniques.
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Ethics approval
This study was performed in line with the principles of the Declaration of Helsinki. Ethics committee decision number 2022/09 − 01 was obtained from Dr. Behçet Uz Children's Hospital for this article. This study was presented as a poster at the 2023 EUPSA congress